Could you attach the fenceNode command from vdsm.log? I suspect that you might have a typo in your "additional options field", or there's an Engine bug leading to"
Ignoring unknown option '=Linux1'
Failed: You have to enter plug number
Please use '-h' for usage

Thread-29261::DEBUG::2013-10-17 12:35:59,131::API::1109::vds::(fenceNode) fenceNode(addr=ucs.lnf.infn.it,port=,agent=cisco_ucs,user=ovc1mgr_user,passwd=XXXX,action=status,secure=,options==Linux1)
Thread-29261::DEBUG::2013-10-17 12:35:59,167::API::1135::vds::(fenceNode) rc 1 in agent=fence_cisco_ucs
ipaddr=ucs.lnf.infn.it
login=ovc1mgr_user
option=status
passwd=XXXX
=Linux1 out err Parse error: Ignoring unknown option '=Linux1'
Failed: You have to enter plug number
Please use '-h' for usage
I attached the screenshot of the configuration where you can see there is no additional equal sign.

(In reply to Eli Mesika from comment #6)
> unable to reproduce (see attachment)
The only chage I see between the original image attached to the bug description and the one attached in comment 7 is that in the original there is a SSH Port in the UI (That should not be there) while in the comment 7 this field is missing.
I suspect that this may be related to https://bugzilla.redhat.com/show_bug.cgi?id=1014513
Note that this bug reported that VdsFenceOptionMapping value was not retrieved with the cluster version, rather, the UI tried to get this value with 'general' version and since there is no such value in DB it got the static value from the ConfigValues.java class :
alom:secure=secure,port=ipport;
apc:secure=secure,port=ipport,slot=port;bladecenter:secure=secure,port=ipport,slot=port;
drac5:secure=secure,port=ipport;
eps:slot=port;ilo:secure=ssl,port=ipport;
ipmilan:;
rsa:secure=secure,port=ipport;
rsb:;
wti:secure=secure,port=ipport,slot=port
Also note that there is no value for cisco_ucs here, so UI preserves the latest selected valid agent fields
should be tested again with the above BZ fix and if the assumption above is correct, I will close that as a duplicate of 1014513